Re-apply patch to fix Ptex includes on Windows.  Broke it with last checkin.
Re-apply patch to fix Ptex includes on Windows.  Broke it with last checkin.

git-svn-id: c3edda122e248ef33995da003806c930f62b9468@1772 31904243-a364-42ac-a3db-9305396518ba

micler/oiio,mcanthony/oiio,scott-wilson/oiio,jeremyselan/oiio,OpenImageIO/oiio,sambler/oiio,mcanthony/oiio,bdeluca/oiio,lgritz/oiio,cwilling/oiio,mcanthony/oiio,sambler/oiio,lgritz/oiio,jeremyselan/oiio,YangYangTL/oiio,scott-wilson/oiio,jeremyselan/oiio,sambler/oiio,micler/oiio,OpenImageIO/oiio,scott-wilson/oiio,YangYangTL/oiio,micler/oiio,cwilling/oiio,scott-wilson/oiio,lgritz/oiio,OpenImageIO/oiio,bdeluca/oiio,bdeluca/oiio,YangYangTL/oiio,mcanthony/oiio,sambler/oiio,cwilling/oiio,micler/oiio,OpenImageIO/oiio,YangYangTL/oiio,bdeluca/oiio,cwilling/oiio,lgritz/oiio